Marques · Clinical and vaccine immunology : CVI 2009 · case-control study · n=30

Natural killer cell counts are not different between patients with post-Lyme disease syndrome and controls.

Cited 58 times in the scientific literature.

Level 4 - case-series / case-control

Small cross-sectional case-control comparison of patient groups and healthy controls.

PubMed 19515868 · doi:10.1128/CVI.00167-09 · record verified 2026-08-28

What was done

Immunophenotyping for natural killer cells (defined by the CD57 marker) was performed across three groups: 9 individuals with post-Lyme disease syndrome, 12 individuals who recovered from Lyme disease, and 9 healthy volunteers.

What was found

The abstract reports that natural killer cell counts were not significantly different between the groups, but provides no specific numerical values, standard deviations, or p-values.

Why it matters

These findings challenge prior claims that decreased CD57 natural killer cell counts act as a distinct biomarker for chronic Lyme disease or post-Lyme disease syndrome.

Limits

The sample size is extremely small (total n = 30 across three arms), creating a high risk of being underpowered to detect modest differences. No exact numerical data or statistical parameters are provided in the abstract.

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